If the name of the page contains the double quotes character ("), the "Edit in word" action from the "Tools" combo box fails to open Word.
Actually, the standard dialog box with the
"The following location is going to be opened on your computer... By the program: C:\Program Files\Microsoft Office\OFFICE11\WINWORD.EXE..."
warning message is not displayed.
Instead, the browser forwards to my Confluence site home page.

One more information: this issue does not happen if the page name contains simple quotes (').

Cf https://developer.atlassian.com/jira/browse/WORDDV-263